Method of forming of the wet fines and coal silts and an equipment suitable for applying the method

ABSTRACT

COAL FINES OR COAL SLIT MATERIALS COMPRISING WATER ARE ADMIXED WITH A BINDING AGENT AND MECHANICALLY MIXED WHILE SUBJECTING SUPERHEATED STEAM AGAINST THE DIRECTION OF THE COAL MIXTURE MOVEMENT.

Aug. 14,1973 M- RUTKOWSK ET A'- 3,752,656

METHOD OF FORMING OF THE WET FINES AND COAL SILTS AND AN EQUIPMENT SUITABLE FOB. APPLYING THE METHOD Filed Feb. lO, 1971 4 ,-0 'fgoooooooooooooo l', l fl 46 7 9 MARIAN RuTKowsKl JADwlGA wu-:cKowsK'A INVENTOR S United lStates Patent O im. ci. crei 5/22; mob 11 /oo U.S. Cl. 44--2 Z Claims ABSTRACT OF THE DISCLGSURE Coal fines or coal silt materials comprising Water are admixed with a binding agent' and mechanically mixed while subjecting superheated steam against the direction of the coal mixture movement.

The subject of present invention is a method of forming of the wet rines and coal silts, and an equipment suitable for applying the method.

Known at present are many methods of forming of line substance assortments into the largerones eg.: forming in briquetting machine of crushed hard coal by means of adhesion bonding agents, heating of coal until 1t reaches its plastic state and then hot forming of thus processed substance, employment of very high pressures for cracking of granular materials, etc. For each of these methods a suitable raw material is needed whose physical and chemical properties must be strictly respected. Most popular and widely used method is forming of crushed hard coal by means of such binding agents as the high-temperature tar pitch or primary tar pitch, sulphite waste liquer, mineral matters such as lime and clay, asphalt, and briquetting viscose. For each binding agent a different technology is required for preparation of briquetting compound. For solid and brittle in the normal temperature binding agent compounds, additional operations are needed such as crushing until a suitable grain-size distribution is obtained, while the agents of a low softening point are delivered to the coal either in a liquid form after heating them up to the temperature above the softening point, or in the form of emulsion. A very important factor while forming the coal is its moisture content, and therefore, in order to obtain the briquettes of a high mechanical strength, the Water content in the output material should be reduced by drying to about 4 percent. Employed for drying of wet materials are hot air, exhaust gases, inert gases such as nitrogen or carbon dioxide, heat generating systems, infra-red radiation, or the energy of the quick alternating electromagnetic field. Using of hot air and exhaust gases for drying is inconvenient since the oxidation of coal takes place. Moreover, an explosive mixture is being produced While the coal dust is blended with gases containing oxygen. Presently known and used means for drying the coal include drum driers in which the material is being shifted by centrifugal force, trough driers in which the material is being mixed by a Worm mechanism, compartment driers equipped with belt conveyor, and pneumatic and fluidization driers.

The object of present invention is to eliminate all the deciencies and inconveniences present with the available and used methods of forming of wet fines and coal silts while its aim consists in developing of a new forming method and designing of an equipment which would be suitable for application of this method.

This object has been attained in such a manner that the wet nes or coal silt which is introduced into the mixing vessel is sprinkled with a binding agent comprising a residue obtained in the treatment of petroleum at the AICC rate of 5-10 percent by Weight in proportion to the Wet fines or coal silt and, while the substance is mixed, it is subjected to the action of super heated to 250 C. steam which is introduced to the mixing vessel at the rate of 1-3 tons per hour in proportion to 1 ton of the wet lines or coal silt and against the direction of the moving coal mixture, said binding agent being such a residue as for instance the distillation residue, pressure still tar, hydro-cracking or pyrolysis residue to which an aluminosilicate catalyzer is added at the temperature of 250 C. in the quantity of 0.5-2 percent by weight in proportion to the residue. The means for application of this method combines a mixing vessel provided with a mechanical mixer coupled with the mechanism of a discharging worm, and a tube ring through which the superheated steam is introduced to the mixing vessel. Each mixer arm of the mixing vessel 1s fitted with a steel scraper which prevents sticking of the mixture to the agitator wall.

Substantial technical advantage oiered by the invented method is comprised in the possibility of conducting the drying process of the -wet iines or coal silt and the process of mixing it with the bindingagent in the form obtained in the treatment of petroleum residue, rWithin a single installation system of a simple construction while the danger of forming of explosive mixtures is entirely eliminated. Further technical vantage point is: that the properties of the end product obtained by application of this method are resembling the value properties of the coals. The substance of invention is depicted in the drawing 1n which presented is the diagram of an equipment developed and suitable for forming of wet iines or coal silts according to the invented method.

EXAMPLE Coal lines or coal silt containing about 30 percent Of water is delivered from a reservoir 1, by means of worm mechanisms 2, to mixing vessel 3 where it is sprinkled with the binding agent at the rate of 10 percent by weight in proportion to the amount of coal lines or coal silt. The binding agent is delivered, by means of a pump 4, from a tank 5 in which the said residue in form of distillation residue, pressure still tar, hydro-crackingor pyrolysis residue. The mixing vessel 3 is provided with a mechanical mixture 7 of high efficiency Whose arms are fitted with steel Scrapers preventing sticking of the mixture to the walls of the mixing vessel, and with a perforated tube ring 8 through which the steam superheated to the temperature of 250 C. is introduced to the agitator of the rate of 2 tous per hour in proportion to l ton of the wet fines or' coal silt, causing heating up of to the coal mixture and evaporation of water to the end water content which lies below the level of 10 percent. The superheated steam fluing the coal mixture, and bringing thus about a better exposition of the surface of coal grains, causes solvation of coal nes or coal silt by the binding agent. For the actual binding of the agent with coal fines or coal silt decisive is the chemical character of the residue itself and physical and chemical properties of coal lines or coal silt which come to the evidence at increased temperature under the presence of steam. Interreaction of these substances and the inlluence of the mentioned factors become more intensive along with the coal-bituminous mixture: moving towards the lower part of mixing vessel 3. After elapsing of about 30 minutes, the coal-bituminous mixture moves to the end part of mixing vessel 3 whence it is delivered, by means of worm mechanism 9 with coupled mixer 7, to the belt conveyor 10, and thence, to the reservoir 11 from which it is delivered to briquetting machine 12. The ow of superheated steam directed against the direction of coal mixture movement is ensured by the exhauster 13 which Patented Aug. 14, 1973 is installed behind the steam convector 14 through which the wet steam having a temperature of about 120 C. is sucked. The wet steam passes, through exhauster 13, to dropping tunnel 15 and thence to la diaphragm heater 16 which can be built, for instance, as a heating coil accommodated in the flue of a thermal-electric power station.

What we claim is:

1. A method of developing shapable wet iines or coal silt material comprising introducing said material into a mixing vessel, admixing a binding agent obtained in the treatment of petroleum with said material in an amount of 5-10% by weight of said material and countercurrently subjecting said mixture to superheated steam at a temperature of 250 C. in an amount of steam of 1 to 3 times the amount of material.

2. An apparatus for creating shapa'ble fines or coal silt comprising a mixing vessel, a means to introduce fines References Cited UNITED STATES PATENTS 2,623,243 12/1952 Jean et al 44-10 R 1,929,860 10/1933 Trent 44-24 2,776,935 1/1957 Jahnig et al. 44-24 X CARL F. DEES, Primary Examiner U.S. Cl. X.R. 44-10 E, 24 

